Applicability

Description

The objective of this technique is to associate each data cell (in a data table) with
the appropriate headers. This technique adds a headers attribute to each
data cell (td element). It also adds an id attribute to any
cell used as a header for other cells. The headers attribute of a cell
contains a list of the id attributes of the associated header cells. If
there is more than one id, they are separated by spaces.

This technique is used when data cells are associated with more than one row and/or one
column header. This allows screen readers to speak the headers associated with each data
cell when the relationships are too complex to be identified using the th
element alone or the th element with the scope attribute.
Using this technique also makes these complex relationships perceivable when the
presentation format changes.

This technique is not recommended for layout tables since its use implies a
relationship between cells that is not meaningful when tables are used for layout.